1. Field of the Invention
The present invention relates to lathe chucks and more particularly pertains to a new and improved lathe chuck which automatically grips stock positioned therein without any requirement of an operator performing additional functional steps to effect such a lockable positioning of the stock within the chuck.
2. Description of the Prior Art
In view of the continuing trend toward the development of automation, many chucking devices utilized on lathes and similar machines are proving to be inadequate to serve their intended function. Additionally, with advances in technology occurring every day, the nature and shapes of material which must be chucked and machined has become much more diversified. Accordingly, there is an increasing demand and necessity for more versatile chucks which are capable of automatically functioning so as to enable precision machining of parts with a minimum of induced stress and strain.
In this respect, conventional chucks which are normally utilizable on lathes, milling machines, and the like, typically require a positioning of a piece of stock or material to be machined therein, and then a subsequent manual operation must be performed by an operator to effect a fixed locking of the stock within the chuck. Typically, this fixed locking of stock requires that an operator use a chuck key or other similar device to effect a manual inwardly directed movement of clamping jaws into engagement with the stock or such movement may be made by hydraulic or air apparatus. As can be appreciated, this operation substantially hampers automatic machining operations which would otherwise eliminate the need for an operator during a machining operation.
There has been at least one attempt to develop an automatic chuck which would eliminate some of the complexities associated with the manual fixed positioning of a piece of stock within a chuck. In this connection, reference is made to U.S. Pat. No. 2,922,657, issued Jan. 26, 1960, to Garrison et al, wherein there is disclosed a bore edge chuck which automatically chucks a workpiece in a free yet positively located condition so that the work may be precision machined as to its peripheral contour, free of any holding distortion. However, the construction of the Garrison et al device is quite complex and utilizes a cam mechanism which effectively grips a workpiece from an interior hollow portion thereof. In this connection, the Garrison et al device is not utilizable on bar stock in a manner whereby clamping shoes are automatically brought into engagement with an exterior surface of the stock.
Accordingly, it can be appreciated that there exists a continuing need for new and improved lathe chucks which automatically and reliably grip bar stock in a working position and which may be easily and economically manufactured. In this connection, the present invention substantially fulfills this need.